Waldorf MiniWorks 4-Pole

The MiniWorks is a stand-alone 4-pole resonant analog filter and
modulation module. Use it to create those Daft-Punk filter sweeps on
entire drum & rhythm loops! Run any sounds, synthesizers or loops
through it and filter them with a truly analog-like VCF (filter) that is
not only very flexible but MIDI controllable as well! There are many
modulation sources that can be programmed between the extensive VCF,
VCA, envelope and LFO sections and these settings can be stored in the
(20) user memory patches. The MiniWorks can also be overloaded for a
lo-fi crunchy sound too! If it were a true stereo filter it would be
perfect (input is mono, output is stereo), but in its price range it is
the best analog filter module available!